This invention relates to an active amino acid Ca product, i.e., a calcium oxide and/or calcium hydroxide product coexistent with a slight amount of one or more amino acids and hydrolyzable amino acid derivatives, beverages containing same, and a process for their production. More particularly, it relates to an active amino acid Ca of natural origin coexistent with a slight amount of one or more amino acids and hydrolyzable amino acid derivatives, which can be effectively absorbed into the human body and can deposit onto the bone with a high efficiency, beverages containing same, and a process for their production.
It has been widely accepted that calcium is an essential element for formation of bone or tooth of mammals as well as human beings. In addition, it has recently been found that calcium is one of the most important elements that support all sorts of life activities and, at present, calcium is receiving much attention in the front line of medical science.
It has been pointed out that deficiency of calcium induces not only osteoporosis but such diseases as hypertension, arteriosclerosis, arthralgia, diabetes, immunological diseases, and obecity ["Kurasi To Kenkou (Life and Health)", 1991, vol.9, published by Hoken Doujin Sha].
However, calcium can be absorbed only at an extremely low absorption ratio unless it is ingested together with vitamin D or proteins, and a necessary amount of calcium can not be absorbed by independent ingestion of calcium.
Recent study has revealed that an adult requires calcium in an amount of 600 mg per day. It is known, however, that calcium contained in foods or beverages is not completely absorbed by the body and that calcium content indicated for a particular food or beverage is greatly different from the amount of calcium actually absorbed therefrom by the body. Therefore, an enormous amount of calcium-containing foods must be ingested in order to take up the necessary amount of calcium from daily meals.
For example, calcium contained in cow's milk which is known as a drink containing calcium at a level as high as about 100 mg/100 ml and is believed to be absorbed with a high absorption ratio due to bonding of calcium to protein, can be absorbed at a level as low as 50% at the highest, i.e., 50 mg out of 100 mg. In addition, the protein bonding to calcium finally produces, after being digested and absorbed, lactic acid, butyric acid, pyroracemic acid, sulfuric acid and phosphoric acid, and most of 50 mg of the absorbed calcium is consumed for neutralizing these acids, thus the amount of calcium substantially absorbed being at most about 10 mg out of 100 ml of cow's milk.
Therefore, it is obvious that a necessary amount of calcium can not be ingested from cow's milk alone. However, in order to supply the deficient amount of calcium from other foods or beverages, even calcium-rich foods such as small dried sardines, sardines, cystophyllum fusiforme, toasted laver, etc. fail to supply the necessary amount of calcium. As a result, human beings are always in a calcium-deficient state, thus suffering from the aforesaid diseases induced by deficiency of calcium.
Such situation is not limited to Japan alone. In Europe and the United States where cow's milk is consumed 3 to 5 times as much as in Japan, incidence of osteoporosis which has been clarified to be induced by deficiency of calcium is twice that in Japan. This fact shows that calcium-rich foods or beverages such as cow's milk are insufficient to solve the problem of calcium deficiency.
Vitamin D known to accelerate absorption of calcium is produced from provitamin D in the body through irradiation with sunlight, or is ingested directly from foods. The thus ingested vitamin D is converted to active vitamin D by the action of accessory thyroid hormone. The active vitamin D helps calcium to be absorbed through intestinal wall The active vitamin D also causes calcium of the bone to be released from the bone in cooperation with the accessory thyroid hormone and, as a result, excess vitamin D is known to induce many troubles such as hypercalcemia, uremia, and malacosteon. Thus, in the USA, FDA does not approve vitamin D a medicine.
As has been described above, even cow's milk, which is believed to show the best calcium absorption ratio, permits calcium contained therein to be absorbed only in an extremely small absorption ratio and, therefore, it is at present extremely difficult to supply a necessary amount of calcium from foods alone. The calcium absorption ratio decreases with age of men or women. It has been clarified that all sorts of diseases and senility are mostly induced by deficiency of calcium from both the microscopic (or cell-level) and macroscopic (or general) points of view (Reports of the Japanese Society of Internal Medicine, Apr., 1990).
That is, when calcium level becomes lower than is necessary for maintaining life, a necessary amount of calcium is supplied from the bone, which in turn damages the bone cells, inducing retardation of growth of bone or tooth and osteoporosis. In addition, general health state will be damaged. For example, purification of blood and healthy state of brain, nerve, heart, muscle, etc. will not be maintained.
Of these diseases, osteoporosis is believed to be the disease to which human beings are most susceptible due to deficiency of calcium. In addition, this disease has been found to produce bedridden old men and old patients suffering from dementia. Thus, it is the most important subject to solve the problem of calcium deficiency for realizing healthy longevity in the coming aging society.
In order to solve the problem of calcium deficiency, calcium-containing products have been developed as nutrition-supplying foods, and calcium-containing preparations for medical use have been required to show higher absorption ratio ["Karusiumu No Subete (Everything on Calcium)" written by Takuo Fujita, issued by Aki Shobo].
Of the calcium-containing products, that one which has been developed by the inventors and which is a purified electrolysis product of oystershell contains more mineral ingredients and shows a higher calcium ion concentration. This electrolysis product has been proved to show a markedly high absorption ratio in the intestines and deposits on the bone in a markedly high ratio, and is now actively employed in many medical facilities including hospitals attached to university as nutrition-supplying food for prophylaxis and treatment of diseases of adults.
In the course of further investigations on the aforesaid calcium-containing product to develop a calcium product showing a higher absorption ratio and a higher deposition ratio on the bone, the inventors have found that a novel active amino acid calcium oxide and/or calcium hydroxide product coexistent with an extremely small amount of amino acids (particularly, low molecular weight amino acids) and hydrolyzable amino acid derivatives can solve the aforesaid problem, thus having completed the present invention.